CVE-2026-54700
ConnectBot SSH: Unbounded SSH field lengths can cause excessive memory allocation
Published Oct 13, 2026
CVSS 4.0 · 6.9 Medium
EPSS < 1%
KEV · Not listed
Description
ConnectBot SSH Client Library is written in Kotlin with Kaitai Struct and KStateMachine. Prior to 0.3.1, the SSH protocol parser trusts attacker-controlled inner byte lengths and element counts without verifying that they fit in the containing packet. A malicious or compromised SSH server can return a small malformed packet whose oversized declarations cause the Kaitai Struct Java runtime to attempt excessive allocation or repeated parsing before detecting truncated input. The general transport path requires a client connection but no authentication or optional feature; malformed SSH-agent messages additionally require SSH agent forwarding. The issue can raise an uncaught OutOfMemoryError and terminate the application process, with no demonstrated confidentiality or integrity impact. This issue is fixed in version 0.3.1.
Affected Products
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CVE record
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NVD configurations
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Red Hat packages
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OpenCVE enrichment
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| connectbot | cbssh | affected |
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No data available yet.
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 Github GHSA |
GHSA-ch3q-cw5r-f4hg | ConnectBot SSH Client Library: Unbounded SSH field lengths can cause excessive memory allocation |
Metrics
Attack Vector Network
Attack Complexity Low
Privileges Required None
Attack Requirements None
User Interaction Active
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.370% probability within 30 days)
Exploitation none
Automatable yes
Technical Impact partial
References
History
Oct 17, 2026 1:30 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Oct 13, 2026 4:00 PM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | ConnectBot SSH Client Library is written in Kotlin with Kaitai Struct and KStateMachine. Prior to 0.3.1, the SSH protocol parser trusts attacker-controlled inner byte lengths and element counts without verifying that they fit in the containing packet. A malicious or compromised SSH server can return a small malformed packet whose oversized declarations cause the Kaitai Struct Java runtime to attempt excessive allocation or repeated parsing before detecting truncated input. The general transport path requires a client connection but no authentication or optional feature; malformed SSH-agent messages additionally require SSH agent forwarding. The issue can raise an uncaught OutOfMemoryError and terminate the application process, with no demonstrated confidentiality or integrity impact. This issue is fixed in version 0.3.1. | |
| Title | ConnectBot SSH: Unbounded SSH field lengths can cause excessive memory allocation | |
| Weaknesses | CWE-20 CWE-789 |
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| References |
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| Metrics |
cvssV4_0
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Subscriptions
No data.
